I never want to read spoilers until after I've watched the show. That applies to everything--anime, movies, wrestling, vidya, you name it.

Worst example: The WWE Smackdown episode where Alberto Del Rio won the World Heavyweight title from The Big Show in a last-man-standing match (This was about 2 weeks ago). Now, keep in mind that while Raw and the pay-per-views are aired live, Smackdown (Bar the occasional live Super Smackdown show), Main Event, and Saturday Morning Slam are all taped. WWE put the dirt sheet for that episode of Smackdown right before it aired. I didn't even bother TiVo'ing it that week. If I'm going to watch wrestling, I'd really rather not read the dirt sheets because it just destroys kayfabe.

I've also got one friend who spoiled Rurouni Kenshin for me on Facebook. He just flat-out posts the ending to it! I never watched that far up on Kenshin, nor have I read the manga, but he still ruined the ending. Then again, he also has a habit of standing in front of people when they're trying to game and never wants to tip the waitress whenever he goes out to eat.

I don't appreciate it when some person carelessly spoils important details in a film/show/anime ect., because then it just takes away from the experience I would of had if I were to see it with no prior knowledge.

Hate them if they are really important or cool elements of something I'm looking forward too. Movie trailers have gotten so bad they basically lay out the whole plot and show you what should be key reveals in a 60 second trailer. I actually refuse to watch the trailers for any movie I actually give a shit about like Iron man 3 or Star Trek... Or if some douche bag posts the results to a UFC title fight before I get to watch it. I can't stand that shit.

Me and my anime friends do it all the time not on purpose just mostly on accident to each other and other fans cause we always assume like us most watch and read whats going on that tends not to be the case.

I like spoilers, sometimes when I watch and anime (or visual novel) I usually check the ending.
Like I was extremlyyyyyyyyyyyyyyyyyyyyyyyyyy lucky that I checked blue drops ending.
That was almost bad as ef.